1. Field of the Invention
The present invention relates to a kit for implanting in a duct, the kit being of the type comprising:                a tubular endoprosthesis; and        a prosthetic valve.        
The heart comprises two atria and two ventricles which are separated by valves. Valves are also present at the outlet from the right ventricle (pulmonary valve) and from the left ventricle (aortic valve).
These valves ensure that blood flows in one direction only, preventing a backflow of blood at the end of ventricular contraction.
Valves can suffer from diseases. In particular, they can suffer from poor opening, thereby reducing blood flow, or from not being fully leaktight, thus allowing backflow or regurgitation towards the ventricle that expels the blood flow.
These problems of regurgitation lead to abnormal dilation of the ventricle which can lead in the long run to heart failure.
2. Description of the Related Art
It is known to treat this type of disease surgically, by replacing the diseased valve. Diseased valves, and in particular the pulmonary valve at the outlet from the right ventricle, are replaced by a valve taken from a deceased donor, or by a bioprosthesis constituted by a metal frame and a shutter made of a tissue of animal origin. The shutter is permanently secured to the frame.
Prosthetic valves are also known. These are constituted by a metal frame supporting a polymer shutter. Such valves are described in particular in documents WO 01/154625 and WO 01/28459.
In such prostheses, the frame is elastically deformable to a small extent only, and the shutter is constituted by a pouch. The elastically deformable frame bears against the inside wall of an organic duct, in particular the pulmonary artery coming from the right ventricle.
It has been found that, after such a prosthesis has been implanted for several years, it degrades and no longer operates effectively. It is then necessary to put a new prosthesis into place.
However, it is not possible to withdraw the old prosthesis in an endoluminar manner, in particular because the carrier frame of the prosthesis has become secured to the heart wall, meaning that they cannot be separated without major surgical intervention for replacing the valve.